lava-worker shares /boot

Greetings,

lava-worker shares /boot in the docker-compose.yml:
https://github.com/ci-box/lava-lab/blob/7289a220b424617c9e7435827d788cbfb8278709/docker-compose.yml#L36
```
    volumes:
      - /boot:/boot 
```

What is that for?

Cheers,
Joe